With Azula already proving that firebenders can master lightning, would firebenders go even further & bend, well, nuclear power?

well as we know nuclear fision needs for us to bombard the nucleus of a redioactive atom with nuetrons and fusion needs extreme heat out of this world to create(or at least make a nuke and place it with extreme amounts of hydrogen atoms make it hit and ENJOY).
I think this wouldnot happen. Firebenders can only go so much as lightning.

First of all, I don't pretend to know much of anything as far as nuclear energy goes...it was the part of my science class I was sleeping during But, from what I understand, it has to do with splitting atoms, and enriching uranium, no? While it is a form of energy, I don't think it's something that the fire benders will create for some time, as it has little to do with fire, or many other natural processes on Earth.

Well as a science major I think I should learn you guys good.
The avatar show has little if any physical realism so what they can and can't do is really up to the writers. But if the avatar show used the four fundamental forces of nature: Zuko: I can bend the strong nuclear force, see!
Aang: aaah I don???t see anything?
Zuko: Well it only has femtometer range, let me see you do better!
Aang: ok well I can bend gravity.
Zuko: Oh ya what could you possibly do with/*squish* (moon falls on zuko crushing him)
Aang: that.

LOL good one dumbtvnut.
Zuko: what was that for?!
Aang: just for laughs.

A detailed enrichment about nuclear energy: fission reaction laymans term - splitting of atoms - when a neutron is bombarded to a highly unstable molecule(ex. uranium)and let it decompose (beta decay mainly) and form new more stable molecules and releases heat while doing so(EXPLOSION in nukes). Fussion reaction - "the power of the sun in the palm of my hands"(spider man) - the reaction used by the sun combining hydrogen atoms with the help of a sudden elevated temperature and pressure. then the whole thing literary becomes self sustained. heat is produced for every combination of hydrogen.(this reaction produces many kinds of radiation(gamma being the deadliest))
Well there you go a not so detailed info.
Note: for further info consult a book.

I advice that for further infromation people check uncyclopedia, wikipedia's successor.

For the heat aspect lightning is roughly as hot as the suface of the sun theoreticaly if you had four or so firebenders tageting one individual point (About the size of a pea) Then you could achieve the needed heat.